xref: /netbsd-src/sys/netinet/ip_carp.c (revision a24efa7dea9f1f56c3bdb15a927d3516792ace1c)
1 /*	$NetBSD: ip_carp.c,v 1.65 2016/05/12 02:24:17 ozaki-r Exp $	*/
2 /*	$OpenBSD: ip_carp.c,v 1.113 2005/11/04 08:11:54 mcbride Exp $	*/
3 
4 /*
5  * Copyright (c) 2002 Michael Shalayeff. All rights reserved.
6  * Copyright (c) 2003 Ryan McBride. All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR OR HIS RELATIVES BE LIABLE FOR ANY DIRECT,
21  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
22  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
23  * SERVICES; LOSS OF MIND, USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
25  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
26  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
27  * THE POSSIBILITY OF SUCH DAMAGE.
28  */
29 
30 #ifdef _KERNEL_OPT
31 #include "opt_inet.h"
32 #include "opt_mbuftrace.h"
33 #endif
34 
35 #include <sys/cdefs.h>
36 __KERNEL_RCSID(0, "$NetBSD: ip_carp.c,v 1.65 2016/05/12 02:24:17 ozaki-r Exp $");
37 
38 /*
39  * TODO:
40  *	- iface reconfigure
41  *	- support for hardware checksum calculations;
42  *
43  */
44 
45 #include <sys/param.h>
46 #include <sys/proc.h>
47 #include <sys/mbuf.h>
48 #include <sys/socket.h>
49 #include <sys/socketvar.h>
50 #include <sys/callout.h>
51 #include <sys/ioctl.h>
52 #include <sys/errno.h>
53 #include <sys/device.h>
54 #include <sys/time.h>
55 #include <sys/kernel.h>
56 #include <sys/kauth.h>
57 #include <sys/sysctl.h>
58 #include <sys/ucred.h>
59 #include <sys/syslog.h>
60 #include <sys/acct.h>
61 #include <sys/cprng.h>
62 
63 #include <sys/cpu.h>
64 
65 #include <net/if.h>
66 #include <net/pfil.h>
67 #include <net/if_types.h>
68 #include <net/if_ether.h>
69 #include <net/route.h>
70 #include <net/netisr.h>
71 #include <net/net_stats.h>
72 #include <netinet/if_inarp.h>
73 
74 #if NFDDI > 0
75 #include <net/if_fddi.h>
76 #endif
77 #if NTOKEN > 0
78 #include <net/if_token.h>
79 #endif
80 
81 #ifdef INET
82 #include <netinet/in.h>
83 #include <netinet/in_systm.h>
84 #include <netinet/in_var.h>
85 #include <netinet/ip.h>
86 #include <netinet/ip_var.h>
87 
88 #include <net/if_dl.h>
89 #endif
90 
91 #ifdef INET6
92 #include <netinet/icmp6.h>
93 #include <netinet/ip6.h>
94 #include <netinet6/ip6_var.h>
95 #include <netinet6/nd6.h>
96 #include <netinet6/scope6_var.h>
97 #endif
98 
99 #include <net/bpf.h>
100 
101 #include <sys/sha1.h>
102 
103 #include <netinet/ip_carp.h>
104 
105 #include "ioconf.h"
106 
107 struct carp_mc_entry {
108 	LIST_ENTRY(carp_mc_entry)	mc_entries;
109 	union {
110 		struct ether_multi	*mcu_enm;
111 	} mc_u;
112 	struct sockaddr_storage		mc_addr;
113 };
114 #define	mc_enm	mc_u.mcu_enm
115 
116 struct carp_softc {
117 	struct ethercom sc_ac;
118 #define	sc_if		sc_ac.ec_if
119 #define	sc_carpdev	sc_ac.ec_if.if_carpdev
120 	int ah_cookie;
121 	int lh_cookie;
122 	struct ip_moptions sc_imo;
123 #ifdef INET6
124 	struct ip6_moptions sc_im6o;
125 #endif /* INET6 */
126 	TAILQ_ENTRY(carp_softc) sc_list;
127 
128 	enum { INIT = 0, BACKUP, MASTER }	sc_state;
129 
130 	int sc_suppress;
131 	int sc_bow_out;
132 
133 	int sc_sendad_errors;
134 #define CARP_SENDAD_MAX_ERRORS	3
135 	int sc_sendad_success;
136 #define CARP_SENDAD_MIN_SUCCESS 3
137 
138 	int sc_vhid;
139 	int sc_advskew;
140 	int sc_naddrs;
141 	int sc_naddrs6;
142 	int sc_advbase;		/* seconds */
143 	int sc_init_counter;
144 	u_int64_t sc_counter;
145 
146 	/* authentication */
147 #define CARP_HMAC_PAD	64
148 	unsigned char sc_key[CARP_KEY_LEN];
149 	unsigned char sc_pad[CARP_HMAC_PAD];
150 	SHA1_CTX sc_sha1;
151 	u_int32_t sc_hashkey[2];
152 
153 	struct callout sc_ad_tmo;	/* advertisement timeout */
154 	struct callout sc_md_tmo;	/* master down timeout */
155 	struct callout sc_md6_tmo;	/* master down timeout */
156 
157 	LIST_HEAD(__carp_mchead, carp_mc_entry)	carp_mc_listhead;
158 };
159 
160 int carp_suppress_preempt = 0;
161 static int carp_opts[CARPCTL_MAXID] = { 0, 1, 0, 0, 0 };	/* XXX for now */
162 
163 static percpu_t *carpstat_percpu;
164 
165 #define	CARP_STATINC(x)		_NET_STATINC(carpstat_percpu, x)
166 
167 #ifdef MBUFTRACE
168 static struct mowner carp_proto_mowner_rx = MOWNER_INIT("carp", "rx");
169 static struct mowner carp_proto_mowner_tx = MOWNER_INIT("carp", "tx");
170 static struct mowner carp_proto6_mowner_rx = MOWNER_INIT("carp6", "rx");
171 static struct mowner carp_proto6_mowner_tx = MOWNER_INIT("carp6", "tx");
172 #endif
173 
174 struct carp_if {
175 	TAILQ_HEAD(, carp_softc) vhif_vrs;
176 	int vhif_nvrs;
177 
178 	struct ifnet *vhif_ifp;
179 };
180 
181 #define	CARP_LOG(sc, s)							\
182 	if (carp_opts[CARPCTL_LOG]) {					\
183 		if (sc)							\
184 			log(LOG_INFO, "%s: ",				\
185 			    (sc)->sc_if.if_xname);			\
186 		else							\
187 			log(LOG_INFO, "carp: ");			\
188 		addlog s;						\
189 		addlog("\n");						\
190 	}
191 
192 static void	carp_hmac_prepare(struct carp_softc *);
193 static void	carp_hmac_generate(struct carp_softc *, u_int32_t *,
194 		    unsigned char *);
195 static int	carp_hmac_verify(struct carp_softc *, u_int32_t *,
196 		    unsigned char *);
197 static void	carp_setroute(struct carp_softc *, int);
198 static void	carp_proto_input_c(struct mbuf *, struct carp_header *,
199 		    sa_family_t);
200 static void	carpdetach(struct carp_softc *);
201 static int	carp_prepare_ad(struct mbuf *, struct carp_softc *,
202 		    struct carp_header *);
203 static void	carp_send_ad_all(void);
204 static void	carp_send_ad(void *);
205 static void	carp_send_arp(struct carp_softc *);
206 static void	carp_master_down(void *);
207 static int	carp_ioctl(struct ifnet *, u_long, void *);
208 static void	carp_start(struct ifnet *);
209 static void	carp_setrun(struct carp_softc *, sa_family_t);
210 static void	carp_set_state(struct carp_softc *, int);
211 static int	carp_addrcount(struct carp_if *, struct in_ifaddr *, int);
212 enum	{ CARP_COUNT_MASTER, CARP_COUNT_RUNNING };
213 
214 static void	carp_multicast_cleanup(struct carp_softc *);
215 static int	carp_set_ifp(struct carp_softc *, struct ifnet *);
216 static void	carp_set_enaddr(struct carp_softc *);
217 #if 0
218 static void	carp_addr_updated(void *);
219 #endif
220 static u_int32_t	carp_hash(struct carp_softc *, u_char *);
221 static int	carp_set_addr(struct carp_softc *, struct sockaddr_in *);
222 static int	carp_join_multicast(struct carp_softc *);
223 #ifdef INET6
224 static void	carp_send_na(struct carp_softc *);
225 static int	carp_set_addr6(struct carp_softc *, struct sockaddr_in6 *);
226 static int	carp_join_multicast6(struct carp_softc *);
227 #endif
228 static int	carp_clone_create(struct if_clone *, int);
229 static int	carp_clone_destroy(struct ifnet *);
230 static int	carp_ether_addmulti(struct carp_softc *, struct ifreq *);
231 static int	carp_ether_delmulti(struct carp_softc *, struct ifreq *);
232 static void	carp_ether_purgemulti(struct carp_softc *);
233 
234 static void	sysctl_net_inet_carp_setup(struct sysctllog **);
235 
236 struct if_clone carp_cloner =
237     IF_CLONE_INITIALIZER("carp", carp_clone_create, carp_clone_destroy);
238 
239 static __inline u_int16_t
240 carp_cksum(struct mbuf *m, int len)
241 {
242 	return (in_cksum(m, len));
243 }
244 
245 static void
246 carp_hmac_prepare(struct carp_softc *sc)
247 {
248 	u_int8_t carp_version = CARP_VERSION, type = CARP_ADVERTISEMENT;
249 	u_int8_t vhid = sc->sc_vhid & 0xff;
250 	SHA1_CTX sha1ctx;
251 	u_int32_t kmd[5];
252 	struct ifaddr *ifa;
253 	int i, found;
254 	struct in_addr last, cur, in;
255 #ifdef INET6
256 	struct in6_addr last6, cur6, in6;
257 #endif /* INET6 */
258 
259 	/* compute ipad from key */
260 	memset(sc->sc_pad, 0, sizeof(sc->sc_pad));
261 	memcpy(sc->sc_pad, sc->sc_key, sizeof(sc->sc_key));
262 	for (i = 0; i < sizeof(sc->sc_pad); i++)
263 		sc->sc_pad[i] ^= 0x36;
264 
265 	/* precompute first part of inner hash */
266 	SHA1Init(&sc->sc_sha1);
267 	SHA1Update(&sc->sc_sha1, sc->sc_pad, sizeof(sc->sc_pad));
268 	SHA1Update(&sc->sc_sha1, (void *)&carp_version, sizeof(carp_version));
269 	SHA1Update(&sc->sc_sha1, (void *)&type, sizeof(type));
270 
271 	/* generate a key for the arpbalance hash, before the vhid is hashed */
272 	memcpy(&sha1ctx, &sc->sc_sha1, sizeof(sha1ctx));
273 	SHA1Final((unsigned char *)kmd, &sha1ctx);
274 	sc->sc_hashkey[0] = kmd[0] ^ kmd[1];
275 	sc->sc_hashkey[1] = kmd[2] ^ kmd[3];
276 
277 	/* the rest of the precomputation */
278 	SHA1Update(&sc->sc_sha1, (void *)&vhid, sizeof(vhid));
279 
280 	/* Hash the addresses from smallest to largest, not interface order */
281 #ifdef INET
282 	cur.s_addr = 0;
283 	do {
284 		found = 0;
285 		last = cur;
286 		cur.s_addr = 0xffffffff;
287 		IFADDR_FOREACH(ifa, &sc->sc_if) {
288 			in.s_addr = ifatoia(ifa)->ia_addr.sin_addr.s_addr;
289 			if (ifa->ifa_addr->sa_family == AF_INET &&
290 			    ntohl(in.s_addr) > ntohl(last.s_addr) &&
291 			    ntohl(in.s_addr) < ntohl(cur.s_addr)) {
292 				cur.s_addr = in.s_addr;
293 				found++;
294 			}
295 		}
296 		if (found)
297 			SHA1Update(&sc->sc_sha1, (void *)&cur, sizeof(cur));
298 	} while (found);
299 #endif /* INET */
300 
301 #ifdef INET6
302 	memset(&cur6, 0x00, sizeof(cur6));
303 	do {
304 		found = 0;
305 		last6 = cur6;
306 		memset(&cur6, 0xff, sizeof(cur6));
307 		IFADDR_FOREACH(ifa, &sc->sc_if) {
308 			in6 = ifatoia6(ifa)->ia_addr.sin6_addr;
309 			if (IN6_IS_ADDR_LINKLOCAL(&in6))
310 				in6.s6_addr16[1] = 0;
311 			if (ifa->ifa_addr->sa_family == AF_INET6 &&
312 			    memcmp(&in6, &last6, sizeof(in6)) > 0 &&
313 			    memcmp(&in6, &cur6, sizeof(in6)) < 0) {
314 				cur6 = in6;
315 				found++;
316 			}
317 		}
318 		if (found)
319 			SHA1Update(&sc->sc_sha1, (void *)&cur6, sizeof(cur6));
320 	} while (found);
321 #endif /* INET6 */
322 
323 	/* convert ipad to opad */
324 	for (i = 0; i < sizeof(sc->sc_pad); i++)
325 		sc->sc_pad[i] ^= 0x36 ^ 0x5c;
326 }
327 
328 static void
329 carp_hmac_generate(struct carp_softc *sc, u_int32_t counter[2],
330     unsigned char md[20])
331 {
332 	SHA1_CTX sha1ctx;
333 
334 	/* fetch first half of inner hash */
335 	memcpy(&sha1ctx, &sc->sc_sha1, sizeof(sha1ctx));
336 
337 	SHA1Update(&sha1ctx, (void *)counter, sizeof(sc->sc_counter));
338 	SHA1Final(md, &sha1ctx);
339 
340 	/* outer hash */
341 	SHA1Init(&sha1ctx);
342 	SHA1Update(&sha1ctx, sc->sc_pad, sizeof(sc->sc_pad));
343 	SHA1Update(&sha1ctx, md, 20);
344 	SHA1Final(md, &sha1ctx);
345 }
346 
347 static int
348 carp_hmac_verify(struct carp_softc *sc, u_int32_t counter[2],
349     unsigned char md[20])
350 {
351 	unsigned char md2[20];
352 
353 	carp_hmac_generate(sc, counter, md2);
354 
355 	return (memcmp(md, md2, sizeof(md2)));
356 }
357 
358 static void
359 carp_setroute(struct carp_softc *sc, int cmd)
360 {
361 	struct ifaddr *ifa;
362 	int s;
363 
364 	KERNEL_LOCK(1, NULL);
365 	s = splsoftnet();
366 	IFADDR_FOREACH(ifa, &sc->sc_if) {
367 		switch (ifa->ifa_addr->sa_family) {
368 		case AF_INET: {
369 			int count = 0;
370 			struct rtentry *rt;
371 			int hr_otherif, nr_ourif;
372 
373 			/*
374 			 * Avoid screwing with the routes if there are other
375 			 * carp interfaces which are master and have the same
376 			 * address.
377 			 */
378 			if (sc->sc_carpdev != NULL &&
379 			    sc->sc_carpdev->if_carp != NULL) {
380 				count = carp_addrcount(
381 				    (struct carp_if *)sc->sc_carpdev->if_carp,
382 				    ifatoia(ifa), CARP_COUNT_MASTER);
383 				if ((cmd == RTM_ADD && count != 1) ||
384 				    (cmd == RTM_DELETE && count != 0))
385 					continue;
386 			}
387 
388 			/* Remove the existing host route, if any */
389 			rtrequest(RTM_DELETE, ifa->ifa_addr,
390 			    ifa->ifa_addr, ifa->ifa_netmask,
391 			    RTF_HOST, NULL);
392 
393 			rt = NULL;
394 			(void)rtrequest(RTM_GET, ifa->ifa_addr, ifa->ifa_addr,
395 			    ifa->ifa_netmask, RTF_HOST, &rt);
396 			hr_otherif = (rt && rt->rt_ifp != &sc->sc_if &&
397 			    (rt->rt_flags & RTF_CONNECTED));
398 			if (rt != NULL) {
399 				rtfree(rt);
400 				rt = NULL;
401 			}
402 
403 			/* Check for a network route on our interface */
404 
405 			rt = NULL;
406 			(void)rtrequest(RTM_GET, ifa->ifa_addr, ifa->ifa_addr,
407 			    ifa->ifa_netmask, 0, &rt);
408 			nr_ourif = (rt && rt->rt_ifp == &sc->sc_if);
409 
410 			switch (cmd) {
411 			case RTM_ADD:
412 				if (hr_otherif) {
413 					ifa->ifa_rtrequest = NULL;
414 					ifa->ifa_flags &= ~RTF_CONNECTED;
415 
416 					rtrequest(RTM_ADD, ifa->ifa_addr,
417 					    ifa->ifa_addr, ifa->ifa_netmask,
418 					    RTF_UP | RTF_HOST, NULL);
419 				}
420 				if (!hr_otherif || nr_ourif || !rt) {
421 					if (nr_ourif &&
422 					    (rt->rt_flags & RTF_CONNECTED) == 0)
423 						rtrequest(RTM_DELETE,
424 						    ifa->ifa_addr,
425 						    ifa->ifa_addr,
426 						    ifa->ifa_netmask, 0, NULL);
427 
428 					ifa->ifa_rtrequest = arp_rtrequest;
429 					ifa->ifa_flags |= RTF_CONNECTED;
430 
431 					if (rtrequest(RTM_ADD, ifa->ifa_addr,
432 					    ifa->ifa_addr, ifa->ifa_netmask, 0,
433 					    NULL) == 0)
434 						ifa->ifa_flags |= IFA_ROUTE;
435 				}
436 				break;
437 			case RTM_DELETE:
438 				break;
439 			default:
440 				break;
441 			}
442 			if (rt != NULL) {
443 				rtfree(rt);
444 				rt = NULL;
445 			}
446 			break;
447 		}
448 
449 #ifdef INET6
450 		case AF_INET6:
451 			if (cmd == RTM_ADD)
452 				in6_ifaddlocal(ifa);
453 			else
454 				in6_ifremlocal(ifa);
455 			break;
456 #endif /* INET6 */
457 		default:
458 			break;
459 		}
460 	}
461 	splx(s);
462 	KERNEL_UNLOCK_ONE(NULL);
463 }
464 
465 /*
466  * process input packet.
467  * we have rearranged checks order compared to the rfc,
468  * but it seems more efficient this way or not possible otherwise.
469  */
470 void
471 carp_proto_input(struct mbuf *m, ...)
472 {
473 	struct ip *ip = mtod(m, struct ip *);
474 	struct carp_softc *sc = NULL;
475 	struct carp_header *ch;
476 	int iplen, len;
477 	va_list ap;
478 
479 	va_start(ap, m);
480 	va_end(ap);
481 
482 	CARP_STATINC(CARP_STAT_IPACKETS);
483 	MCLAIM(m, &carp_proto_mowner_rx);
484 
485 	if (!carp_opts[CARPCTL_ALLOW]) {
486 		m_freem(m);
487 		return;
488 	}
489 
490 	/* check if received on a valid carp interface */
491 	if (m->m_pkthdr.rcvif->if_type != IFT_CARP) {
492 		CARP_STATINC(CARP_STAT_BADIF);
493 		CARP_LOG(sc, ("packet received on non-carp interface: %s",
494 		    m->m_pkthdr.rcvif->if_xname));
495 		m_freem(m);
496 		return;
497 	}
498 
499 	/* verify that the IP TTL is 255.  */
500 	if (ip->ip_ttl != CARP_DFLTTL) {
501 		CARP_STATINC(CARP_STAT_BADTTL);
502 		CARP_LOG(sc, ("received ttl %d != %d on %s", ip->ip_ttl,
503 		    CARP_DFLTTL, m->m_pkthdr.rcvif->if_xname));
504 		m_freem(m);
505 		return;
506 	}
507 
508 	/*
509 	 * verify that the received packet length is
510 	 * equal to the CARP header
511 	 */
512 	iplen = ip->ip_hl << 2;
513 	len = iplen + sizeof(*ch);
514 	if (len > m->m_pkthdr.len) {
515 		CARP_STATINC(CARP_STAT_BADLEN);
516 		CARP_LOG(sc, ("packet too short %d on %s", m->m_pkthdr.len,
517 		    m->m_pkthdr.rcvif->if_xname));
518 		m_freem(m);
519 		return;
520 	}
521 
522 	if ((m = m_pullup(m, len)) == NULL) {
523 		CARP_STATINC(CARP_STAT_HDROPS);
524 		return;
525 	}
526 	ip = mtod(m, struct ip *);
527 	ch = (struct carp_header *)((char *)ip + iplen);
528 	/* verify the CARP checksum */
529 	m->m_data += iplen;
530 	if (carp_cksum(m, len - iplen)) {
531 		CARP_STATINC(CARP_STAT_BADSUM);
532 		CARP_LOG(sc, ("checksum failed on %s",
533 		    m->m_pkthdr.rcvif->if_xname));
534 		m_freem(m);
535 		return;
536 	}
537 	m->m_data -= iplen;
538 
539 	carp_proto_input_c(m, ch, AF_INET);
540 }
541 
542 #ifdef INET6
543 int
544 carp6_proto_input(struct mbuf **mp, int *offp, int proto)
545 {
546 	struct mbuf *m = *mp;
547 	struct carp_softc *sc = NULL;
548 	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
549 	struct carp_header *ch;
550 	u_int len;
551 
552 	CARP_STATINC(CARP_STAT_IPACKETS6);
553 	MCLAIM(m, &carp_proto6_mowner_rx);
554 
555 	if (!carp_opts[CARPCTL_ALLOW]) {
556 		m_freem(m);
557 		return (IPPROTO_DONE);
558 	}
559 
560 	/* check if received on a valid carp interface */
561 	if (m->m_pkthdr.rcvif->if_type != IFT_CARP) {
562 		CARP_STATINC(CARP_STAT_BADIF);
563 		CARP_LOG(sc, ("packet received on non-carp interface: %s",
564 		    m->m_pkthdr.rcvif->if_xname));
565 		m_freem(m);
566 		return (IPPROTO_DONE);
567 	}
568 
569 	/* verify that the IP TTL is 255 */
570 	if (ip6->ip6_hlim != CARP_DFLTTL) {
571 		CARP_STATINC(CARP_STAT_BADTTL);
572 		CARP_LOG(sc, ("received ttl %d != %d on %s", ip6->ip6_hlim,
573 		    CARP_DFLTTL, m->m_pkthdr.rcvif->if_xname));
574 		m_freem(m);
575 		return (IPPROTO_DONE);
576 	}
577 
578 	/* verify that we have a complete carp packet */
579 	len = m->m_len;
580 	IP6_EXTHDR_GET(ch, struct carp_header *, m, *offp, sizeof(*ch));
581 	if (ch == NULL) {
582 		CARP_STATINC(CARP_STAT_BADLEN);
583 		CARP_LOG(sc, ("packet size %u too small", len));
584 		return (IPPROTO_DONE);
585 	}
586 
587 
588 	/* verify the CARP checksum */
589 	m->m_data += *offp;
590 	if (carp_cksum(m, sizeof(*ch))) {
591 		CARP_STATINC(CARP_STAT_BADSUM);
592 		CARP_LOG(sc, ("checksum failed, on %s",
593 		    m->m_pkthdr.rcvif->if_xname));
594 		m_freem(m);
595 		return (IPPROTO_DONE);
596 	}
597 	m->m_data -= *offp;
598 
599 	carp_proto_input_c(m, ch, AF_INET6);
600 	return (IPPROTO_DONE);
601 }
602 #endif /* INET6 */
603 
604 static void
605 carp_proto_input_c(struct mbuf *m, struct carp_header *ch, sa_family_t af)
606 {
607 	struct carp_softc *sc;
608 	u_int64_t tmp_counter;
609 	struct timeval sc_tv, ch_tv;
610 
611 	TAILQ_FOREACH(sc, &((struct carp_if *)
612 	    m->m_pkthdr.rcvif->if_carpdev->if_carp)->vhif_vrs, sc_list)
613 		if (sc->sc_vhid == ch->carp_vhid)
614 			break;
615 
616 	if (!sc || (sc->sc_if.if_flags & (IFF_UP|IFF_RUNNING)) !=
617 	    (IFF_UP|IFF_RUNNING)) {
618 		CARP_STATINC(CARP_STAT_BADVHID);
619 		m_freem(m);
620 		return;
621 	}
622 
623 	/*
624 	 * Check if our own advertisement was duplicated
625 	 * from a non simplex interface.
626 	 * XXX If there is no address on our physical interface
627 	 * there is no way to distinguish our ads from the ones
628 	 * another carp host might have sent us.
629 	 */
630 	if ((sc->sc_carpdev->if_flags & IFF_SIMPLEX) == 0) {
631 		struct sockaddr sa;
632 		struct ifaddr *ifa;
633 
634 		memset(&sa, 0, sizeof(sa));
635 		sa.sa_family = af;
636 		ifa = ifaof_ifpforaddr(&sa, sc->sc_carpdev);
637 
638 		if (ifa && af == AF_INET) {
639 			struct ip *ip = mtod(m, struct ip *);
640 			if (ip->ip_src.s_addr ==
641 					ifatoia(ifa)->ia_addr.sin_addr.s_addr) {
642 				m_freem(m);
643 				return;
644 			}
645 		}
646 #ifdef INET6
647 		if (ifa && af == AF_INET6) {
648 			struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
649 			struct in6_addr in6_src, in6_found;
650 
651 			in6_src = ip6->ip6_src;
652 			in6_found = ifatoia6(ifa)->ia_addr.sin6_addr;
653 			if (IN6_IS_ADDR_LINKLOCAL(&in6_src))
654 				in6_src.s6_addr16[1] = 0;
655 			if (IN6_IS_ADDR_LINKLOCAL(&in6_found))
656 				in6_found.s6_addr16[1] = 0;
657 			if (IN6_ARE_ADDR_EQUAL(&in6_src, &in6_found)) {
658 				m_freem(m);
659 				return;
660 			}
661 		}
662 #endif /* INET6 */
663 	}
664 
665 	nanotime(&sc->sc_if.if_lastchange);
666 	sc->sc_if.if_ipackets++;
667 	sc->sc_if.if_ibytes += m->m_pkthdr.len;
668 
669 	/* verify the CARP version. */
670 	if (ch->carp_version != CARP_VERSION) {
671 		CARP_STATINC(CARP_STAT_BADVER);
672 		sc->sc_if.if_ierrors++;
673 		CARP_LOG(sc, ("invalid version %d != %d",
674 		    ch->carp_version, CARP_VERSION));
675 		m_freem(m);
676 		return;
677 	}
678 
679 	/* verify the hash */
680 	if (carp_hmac_verify(sc, ch->carp_counter, ch->carp_md)) {
681 		CARP_STATINC(CARP_STAT_BADAUTH);
682 		sc->sc_if.if_ierrors++;
683 		CARP_LOG(sc, ("incorrect hash"));
684 		m_freem(m);
685 		return;
686 	}
687 
688 	tmp_counter = ntohl(ch->carp_counter[0]);
689 	tmp_counter = tmp_counter<<32;
690 	tmp_counter += ntohl(ch->carp_counter[1]);
691 
692 	/* XXX Replay protection goes here */
693 
694 	sc->sc_init_counter = 0;
695 	sc->sc_counter = tmp_counter;
696 
697 
698 	sc_tv.tv_sec = sc->sc_advbase;
699 	if (carp_suppress_preempt && sc->sc_advskew <  240)
700 		sc_tv.tv_usec = 240 * 1000000 / 256;
701 	else
702 		sc_tv.tv_usec = sc->sc_advskew * 1000000 / 256;
703 	ch_tv.tv_sec = ch->carp_advbase;
704 	ch_tv.tv_usec = ch->carp_advskew * 1000000 / 256;
705 
706 	switch (sc->sc_state) {
707 	case INIT:
708 		break;
709 	case MASTER:
710 		/*
711 		 * If we receive an advertisement from a backup who's going to
712 		 * be more frequent than us, go into BACKUP state.
713 		 */
714 		if (timercmp(&sc_tv, &ch_tv, >) ||
715 		    timercmp(&sc_tv, &ch_tv, ==)) {
716 			callout_stop(&sc->sc_ad_tmo);
717 			CARP_LOG(sc, ("MASTER -> BACKUP (more frequent advertisement received)"));
718 			carp_set_state(sc, BACKUP);
719 			carp_setrun(sc, 0);
720 			carp_setroute(sc, RTM_DELETE);
721 		}
722 		break;
723 	case BACKUP:
724 		/*
725 		 * If we're pre-empting masters who advertise slower than us,
726 		 * and this one claims to be slower, treat him as down.
727 		 */
728 		if (carp_opts[CARPCTL_PREEMPT] && timercmp(&sc_tv, &ch_tv, <)) {
729 			CARP_LOG(sc, ("BACKUP -> MASTER (preempting a slower master)"));
730 			carp_master_down(sc);
731 			break;
732 		}
733 
734 		/*
735 		 *  If the master is going to advertise at such a low frequency
736 		 *  that he's guaranteed to time out, we'd might as well just
737 		 *  treat him as timed out now.
738 		 */
739 		sc_tv.tv_sec = sc->sc_advbase * 3;
740 		if (timercmp(&sc_tv, &ch_tv, <)) {
741 			CARP_LOG(sc, ("BACKUP -> MASTER (master timed out)"));
742 			carp_master_down(sc);
743 			break;
744 		}
745 
746 		/*
747 		 * Otherwise, we reset the counter and wait for the next
748 		 * advertisement.
749 		 */
750 		carp_setrun(sc, af);
751 		break;
752 	}
753 
754 	m_freem(m);
755 	return;
756 }
757 
758 /*
759  * Interface side of the CARP implementation.
760  */
761 
762 /* ARGSUSED */
763 void
764 carpattach(int n)
765 {
766 	if_clone_attach(&carp_cloner);
767 
768 	carpstat_percpu = percpu_alloc(sizeof(uint64_t) * CARP_NSTATS);
769 }
770 
771 static int
772 carp_clone_create(struct if_clone *ifc, int unit)
773 {
774 	extern int ifqmaxlen;
775 	struct carp_softc *sc;
776 	struct ifnet *ifp;
777 
778 	sc = malloc(sizeof(*sc), M_DEVBUF, M_NOWAIT|M_ZERO);
779 	if (!sc)
780 		return (ENOMEM);
781 
782 	sc->sc_suppress = 0;
783 	sc->sc_advbase = CARP_DFLTINTV;
784 	sc->sc_vhid = -1;	/* required setting */
785 	sc->sc_advskew = 0;
786 	sc->sc_init_counter = 1;
787 	sc->sc_naddrs = sc->sc_naddrs6 = 0;
788 #ifdef INET6
789 	sc->sc_im6o.im6o_multicast_hlim = CARP_DFLTTL;
790 #endif /* INET6 */
791 
792 	callout_init(&sc->sc_ad_tmo, 0);
793 	callout_init(&sc->sc_md_tmo, 0);
794 	callout_init(&sc->sc_md6_tmo, 0);
795 
796 	callout_setfunc(&sc->sc_ad_tmo, carp_send_ad, sc);
797 	callout_setfunc(&sc->sc_md_tmo, carp_master_down, sc);
798 	callout_setfunc(&sc->sc_md6_tmo, carp_master_down, sc);
799 
800 	LIST_INIT(&sc->carp_mc_listhead);
801 	ifp = &sc->sc_if;
802 	ifp->if_softc = sc;
803 	snprintf(ifp->if_xname, sizeof ifp->if_xname, "%s%d", ifc->ifc_name,
804 	    unit);
805 	ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
806 	ifp->if_ioctl = carp_ioctl;
807 	ifp->if_start = carp_start;
808 	ifp->if_output = carp_output;
809 	ifp->if_type = IFT_CARP;
810 	ifp->if_addrlen = ETHER_ADDR_LEN;
811 	ifp->if_hdrlen = ETHER_HDR_LEN;
812 	ifp->if_mtu = ETHERMTU;
813 	IFQ_SET_MAXLEN(&ifp->if_snd, ifqmaxlen);
814 	IFQ_SET_READY(&ifp->if_snd);
815 	if_attach(ifp);
816 
817 	if_alloc_sadl(ifp);
818 	ifp->if_broadcastaddr = etherbroadcastaddr;
819 	carp_set_enaddr(sc);
820 	LIST_INIT(&sc->sc_ac.ec_multiaddrs);
821 	bpf_attach(ifp, DLT_EN10MB, ETHER_HDR_LEN);
822 #ifdef MBUFTRACE
823 	strlcpy(sc->sc_ac.ec_tx_mowner.mo_name, ifp->if_xname,
824 	    sizeof(sc->sc_ac.ec_tx_mowner.mo_name));
825 	strlcpy(sc->sc_ac.ec_tx_mowner.mo_descr, "tx",
826 	    sizeof(sc->sc_ac.ec_tx_mowner.mo_descr));
827 	strlcpy(sc->sc_ac.ec_rx_mowner.mo_name, ifp->if_xname,
828 	    sizeof(sc->sc_ac.ec_rx_mowner.mo_name));
829 	strlcpy(sc->sc_ac.ec_rx_mowner.mo_descr, "rx",
830 	    sizeof(sc->sc_ac.ec_rx_mowner.mo_descr));
831 	MOWNER_ATTACH(&sc->sc_ac.ec_tx_mowner);
832 	MOWNER_ATTACH(&sc->sc_ac.ec_rx_mowner);
833 	ifp->if_mowner = &sc->sc_ac.ec_tx_mowner;
834 #endif
835 	return (0);
836 }
837 
838 static int
839 carp_clone_destroy(struct ifnet *ifp)
840 {
841 	struct carp_softc *sc = ifp->if_softc;
842 
843 	carpdetach(ifp->if_softc);
844 	ether_ifdetach(ifp);
845 	if_detach(ifp);
846 	callout_destroy(&sc->sc_ad_tmo);
847 	callout_destroy(&sc->sc_md_tmo);
848 	callout_destroy(&sc->sc_md6_tmo);
849 	free(ifp->if_softc, M_DEVBUF);
850 
851 	return (0);
852 }
853 
854 static void
855 carpdetach(struct carp_softc *sc)
856 {
857 	struct carp_if *cif;
858 	int s;
859 
860 	callout_stop(&sc->sc_ad_tmo);
861 	callout_stop(&sc->sc_md_tmo);
862 	callout_stop(&sc->sc_md6_tmo);
863 
864 	if (sc->sc_suppress)
865 		carp_suppress_preempt--;
866 	sc->sc_suppress = 0;
867 
868 	if (sc->sc_sendad_errors >= CARP_SENDAD_MAX_ERRORS)
869 		carp_suppress_preempt--;
870 	sc->sc_sendad_errors = 0;
871 
872 	carp_set_state(sc, INIT);
873 	sc->sc_if.if_flags &= ~IFF_UP;
874 	carp_setrun(sc, 0);
875 	carp_multicast_cleanup(sc);
876 
877 	KERNEL_LOCK(1, NULL);
878 	s = splnet();
879 	if (sc->sc_carpdev != NULL) {
880 		/* XXX linkstatehook removal */
881 		cif = (struct carp_if *)sc->sc_carpdev->if_carp;
882 		TAILQ_REMOVE(&cif->vhif_vrs, sc, sc_list);
883 		if (!--cif->vhif_nvrs) {
884 			ifpromisc(sc->sc_carpdev, 0);
885 			sc->sc_carpdev->if_carp = NULL;
886 			free(cif, M_IFADDR);
887 		}
888 	}
889 	sc->sc_carpdev = NULL;
890 	splx(s);
891 	KERNEL_UNLOCK_ONE(NULL);
892 }
893 
894 /* Detach an interface from the carp. */
895 void
896 carp_ifdetach(struct ifnet *ifp)
897 {
898 	struct carp_softc *sc, *nextsc;
899 	struct carp_if *cif = (struct carp_if *)ifp->if_carp;
900 
901 	for (sc = TAILQ_FIRST(&cif->vhif_vrs); sc; sc = nextsc) {
902 		nextsc = TAILQ_NEXT(sc, sc_list);
903 		carpdetach(sc);
904 	}
905 }
906 
907 static int
908 carp_prepare_ad(struct mbuf *m, struct carp_softc *sc,
909     struct carp_header *ch)
910 {
911 	if (sc->sc_init_counter) {
912 		/* this could also be seconds since unix epoch */
913 		sc->sc_counter = cprng_fast64();
914 	} else
915 		sc->sc_counter++;
916 
917 	ch->carp_counter[0] = htonl((sc->sc_counter>>32)&0xffffffff);
918 	ch->carp_counter[1] = htonl(sc->sc_counter&0xffffffff);
919 
920 	carp_hmac_generate(sc, ch->carp_counter, ch->carp_md);
921 
922 	return (0);
923 }
924 
925 static void
926 carp_send_ad_all(void)
927 {
928 	struct ifnet *ifp;
929 	struct carp_if *cif;
930 	struct carp_softc *vh;
931 	int s;
932 	int bound = curlwp->l_pflag & LP_BOUND;
933 
934 	curlwp->l_pflag |= LP_BOUND;
935 	s = pserialize_read_enter();
936 	IFNET_READER_FOREACH(ifp) {
937 		struct psref psref;
938 		if (ifp->if_carp == NULL || ifp->if_type == IFT_CARP)
939 			continue;
940 
941 		psref_acquire(&psref, &ifp->if_psref, ifnet_psref_class);
942 		pserialize_read_exit(s);
943 
944 		cif = (struct carp_if *)ifp->if_carp;
945 		TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
946 			if ((vh->sc_if.if_flags & (IFF_UP|IFF_RUNNING)) ==
947 			    (IFF_UP|IFF_RUNNING) && vh->sc_state == MASTER)
948 				carp_send_ad(vh);
949 		}
950 
951 		s = pserialize_read_enter();
952 		psref_release(&psref, &ifp->if_psref, ifnet_psref_class);
953 	}
954 	pserialize_read_exit(s);
955 	curlwp->l_pflag ^= bound ^ LP_BOUND;
956 }
957 
958 
959 static void
960 carp_send_ad(void *v)
961 {
962 	struct carp_header ch;
963 	struct timeval tv;
964 	struct carp_softc *sc = v;
965 	struct carp_header *ch_ptr;
966 	struct mbuf *m;
967 	int error, len, advbase, advskew, s;
968 	struct ifaddr *ifa;
969 	struct sockaddr sa;
970 
971 	KERNEL_LOCK(1, NULL);
972 	s = splsoftnet();
973 
974 	advbase = advskew = 0; /* Sssssh compiler */
975 	if (sc->sc_carpdev == NULL) {
976 		sc->sc_if.if_oerrors++;
977 		goto retry_later;
978 	}
979 
980 	/* bow out if we've gone to backup (the carp interface is going down) */
981 	if (sc->sc_bow_out) {
982 		sc->sc_bow_out = 0;
983 		advbase = 255;
984 		advskew = 255;
985 	} else {
986 		advbase = sc->sc_advbase;
987 		if (!carp_suppress_preempt || sc->sc_advskew > 240)
988 			advskew = sc->sc_advskew;
989 		else
990 			advskew = 240;
991 		tv.tv_sec = advbase;
992 		tv.tv_usec = advskew * 1000000 / 256;
993 	}
994 
995 	ch.carp_version = CARP_VERSION;
996 	ch.carp_type = CARP_ADVERTISEMENT;
997 	ch.carp_vhid = sc->sc_vhid;
998 	ch.carp_advbase = advbase;
999 	ch.carp_advskew = advskew;
1000 	ch.carp_authlen = 7;	/* XXX DEFINE */
1001 	ch.carp_pad1 = 0;	/* must be zero */
1002 	ch.carp_cksum = 0;
1003 
1004 
1005 #ifdef INET
1006 	if (sc->sc_naddrs) {
1007 		struct ip *ip;
1008 
1009 		MGETHDR(m, M_DONTWAIT, MT_HEADER);
1010 		if (m == NULL) {
1011 			sc->sc_if.if_oerrors++;
1012 			CARP_STATINC(CARP_STAT_ONOMEM);
1013 			/* XXX maybe less ? */
1014 			goto retry_later;
1015 		}
1016 		MCLAIM(m, &carp_proto_mowner_tx);
1017 		len = sizeof(*ip) + sizeof(ch);
1018 		m->m_pkthdr.len = len;
1019 		m->m_pkthdr.rcvif = NULL;
1020 		m->m_len = len;
1021 		MH_ALIGN(m, m->m_len);
1022 		m->m_flags |= M_MCAST;
1023 		ip = mtod(m, struct ip *);
1024 		ip->ip_v = IPVERSION;
1025 		ip->ip_hl = sizeof(*ip) >> 2;
1026 		ip->ip_tos = IPTOS_LOWDELAY;
1027 		ip->ip_len = htons(len);
1028 		ip->ip_id = 0;	/* no need for id, we don't support fragments */
1029 		ip->ip_off = htons(IP_DF);
1030 		ip->ip_ttl = CARP_DFLTTL;
1031 		ip->ip_p = IPPROTO_CARP;
1032 		ip->ip_sum = 0;
1033 
1034 		memset(&sa, 0, sizeof(sa));
1035 		sa.sa_family = AF_INET;
1036 		ifa = ifaof_ifpforaddr(&sa, sc->sc_carpdev);
1037 		if (ifa == NULL)
1038 			ip->ip_src.s_addr = 0;
1039 		else
1040 			ip->ip_src.s_addr =
1041 			    ifatoia(ifa)->ia_addr.sin_addr.s_addr;
1042 		ip->ip_dst.s_addr = INADDR_CARP_GROUP;
1043 
1044 		ch_ptr = (struct carp_header *)(&ip[1]);
1045 		memcpy(ch_ptr, &ch, sizeof(ch));
1046 		if (carp_prepare_ad(m, sc, ch_ptr))
1047 			goto retry_later;
1048 
1049 		m->m_data += sizeof(*ip);
1050 		ch_ptr->carp_cksum = carp_cksum(m, len - sizeof(*ip));
1051 		m->m_data -= sizeof(*ip);
1052 
1053 		nanotime(&sc->sc_if.if_lastchange);
1054 		sc->sc_if.if_opackets++;
1055 		sc->sc_if.if_obytes += len;
1056 		CARP_STATINC(CARP_STAT_OPACKETS);
1057 
1058 		error = ip_output(m, NULL, NULL, IP_RAWOUTPUT, &sc->sc_imo,
1059 		    NULL);
1060 		if (error) {
1061 			if (error == ENOBUFS)
1062 				CARP_STATINC(CARP_STAT_ONOMEM);
1063 			else
1064 				CARP_LOG(sc, ("ip_output failed: %d", error));
1065 			sc->sc_if.if_oerrors++;
1066 			if (sc->sc_sendad_errors < INT_MAX)
1067 				sc->sc_sendad_errors++;
1068 			if (sc->sc_sendad_errors == CARP_SENDAD_MAX_ERRORS) {
1069 				carp_suppress_preempt++;
1070 				if (carp_suppress_preempt == 1)
1071 					carp_send_ad_all();
1072 			}
1073 			sc->sc_sendad_success = 0;
1074 		} else {
1075 			if (sc->sc_sendad_errors >= CARP_SENDAD_MAX_ERRORS) {
1076 				if (++sc->sc_sendad_success >=
1077 				    CARP_SENDAD_MIN_SUCCESS) {
1078 					carp_suppress_preempt--;
1079 					sc->sc_sendad_errors = 0;
1080 				}
1081 			} else
1082 				sc->sc_sendad_errors = 0;
1083 		}
1084 	}
1085 #endif /* INET */
1086 #ifdef INET6
1087 	if (sc->sc_naddrs6) {
1088 		struct ip6_hdr *ip6;
1089 
1090 		MGETHDR(m, M_DONTWAIT, MT_HEADER);
1091 		if (m == NULL) {
1092 			sc->sc_if.if_oerrors++;
1093 			CARP_STATINC(CARP_STAT_ONOMEM);
1094 			/* XXX maybe less ? */
1095 			goto retry_later;
1096 		}
1097 		MCLAIM(m, &carp_proto6_mowner_tx);
1098 		len = sizeof(*ip6) + sizeof(ch);
1099 		m->m_pkthdr.len = len;
1100 		m->m_pkthdr.rcvif = NULL;
1101 		m->m_len = len;
1102 		MH_ALIGN(m, m->m_len);
1103 		m->m_flags |= M_MCAST;
1104 		ip6 = mtod(m, struct ip6_hdr *);
1105 		memset(ip6, 0, sizeof(*ip6));
1106 		ip6->ip6_vfc |= IPV6_VERSION;
1107 		ip6->ip6_hlim = CARP_DFLTTL;
1108 		ip6->ip6_nxt = IPPROTO_CARP;
1109 
1110 		/* set the source address */
1111 		memset(&sa, 0, sizeof(sa));
1112 		sa.sa_family = AF_INET6;
1113 		ifa = ifaof_ifpforaddr(&sa, sc->sc_carpdev);
1114 		if (ifa == NULL)	/* This should never happen with IPv6 */
1115 			memset(&ip6->ip6_src, 0, sizeof(struct in6_addr));
1116 		else
1117 			bcopy(ifatoia6(ifa)->ia_addr.sin6_addr.s6_addr,
1118 			    &ip6->ip6_src, sizeof(struct in6_addr));
1119 		/* set the multicast destination */
1120 
1121 		ip6->ip6_dst.s6_addr16[0] = htons(0xff02);
1122 		ip6->ip6_dst.s6_addr8[15] = 0x12;
1123 		if (in6_setscope(&ip6->ip6_dst, sc->sc_carpdev, NULL) != 0) {
1124 			sc->sc_if.if_oerrors++;
1125 			m_freem(m);
1126 			CARP_LOG(sc, ("in6_setscope failed"));
1127 			goto retry_later;
1128 		}
1129 
1130 		ch_ptr = (struct carp_header *)(&ip6[1]);
1131 		memcpy(ch_ptr, &ch, sizeof(ch));
1132 		if (carp_prepare_ad(m, sc, ch_ptr))
1133 			goto retry_later;
1134 
1135 		m->m_data += sizeof(*ip6);
1136 		ch_ptr->carp_cksum = carp_cksum(m, len - sizeof(*ip6));
1137 		m->m_data -= sizeof(*ip6);
1138 
1139 		nanotime(&sc->sc_if.if_lastchange);
1140 		sc->sc_if.if_opackets++;
1141 		sc->sc_if.if_obytes += len;
1142 		CARP_STATINC(CARP_STAT_OPACKETS6);
1143 
1144 		error = ip6_output(m, NULL, NULL, 0, &sc->sc_im6o, NULL, NULL);
1145 		if (error) {
1146 			if (error == ENOBUFS)
1147 				CARP_STATINC(CARP_STAT_ONOMEM);
1148 			else
1149 				CARP_LOG(sc, ("ip6_output failed: %d", error));
1150 			sc->sc_if.if_oerrors++;
1151 			if (sc->sc_sendad_errors < INT_MAX)
1152 				sc->sc_sendad_errors++;
1153 			if (sc->sc_sendad_errors == CARP_SENDAD_MAX_ERRORS) {
1154 				carp_suppress_preempt++;
1155 				if (carp_suppress_preempt == 1)
1156 					carp_send_ad_all();
1157 			}
1158 			sc->sc_sendad_success = 0;
1159 		} else {
1160 			if (sc->sc_sendad_errors >= CARP_SENDAD_MAX_ERRORS) {
1161 				if (++sc->sc_sendad_success >=
1162 				    CARP_SENDAD_MIN_SUCCESS) {
1163 					carp_suppress_preempt--;
1164 					sc->sc_sendad_errors = 0;
1165 				}
1166 			} else
1167 				sc->sc_sendad_errors = 0;
1168 		}
1169 	}
1170 #endif /* INET6 */
1171 
1172 retry_later:
1173 	splx(s);
1174 	KERNEL_UNLOCK_ONE(NULL);
1175 	if (advbase != 255 || advskew != 255)
1176 		callout_schedule(&sc->sc_ad_tmo, tvtohz(&tv));
1177 }
1178 
1179 /*
1180  * Broadcast a gratuitous ARP request containing
1181  * the virtual router MAC address for each IP address
1182  * associated with the virtual router.
1183  */
1184 static void
1185 carp_send_arp(struct carp_softc *sc)
1186 {
1187 	struct ifaddr *ifa;
1188 	struct in_addr *in;
1189 	int s;
1190 
1191 	KERNEL_LOCK(1, NULL);
1192 	s = splsoftnet();
1193 	IFADDR_FOREACH(ifa, &sc->sc_if) {
1194 
1195 		if (ifa->ifa_addr->sa_family != AF_INET)
1196 			continue;
1197 
1198 		in = &ifatoia(ifa)->ia_addr.sin_addr;
1199 		arprequest(sc->sc_carpdev, in, in, CLLADDR(sc->sc_if.if_sadl));
1200 	}
1201 	splx(s);
1202 	KERNEL_UNLOCK_ONE(NULL);
1203 }
1204 
1205 #ifdef INET6
1206 static void
1207 carp_send_na(struct carp_softc *sc)
1208 {
1209 	struct ifaddr *ifa;
1210 	struct in6_addr *in6;
1211 	static struct in6_addr mcast = IN6ADDR_LINKLOCAL_ALLNODES_INIT;
1212 	int s;
1213 
1214 	KERNEL_LOCK(1, NULL);
1215 	s = splsoftnet();
1216 
1217 	IFADDR_FOREACH(ifa, &sc->sc_if) {
1218 
1219 		if (ifa->ifa_addr->sa_family != AF_INET6)
1220 			continue;
1221 
1222 		in6 = &ifatoia6(ifa)->ia_addr.sin6_addr;
1223 		nd6_na_output(sc->sc_carpdev, &mcast, in6,
1224 		    ND_NA_FLAG_OVERRIDE, 1, NULL);
1225 	}
1226 	splx(s);
1227 	KERNEL_UNLOCK_ONE(NULL);
1228 }
1229 #endif /* INET6 */
1230 
1231 /*
1232  * Based on bridge_hash() in if_bridge.c
1233  */
1234 #define	mix(a,b,c) \
1235 	do {						\
1236 		a -= b; a -= c; a ^= (c >> 13);		\
1237 		b -= c; b -= a; b ^= (a << 8);		\
1238 		c -= a; c -= b; c ^= (b >> 13);		\
1239 		a -= b; a -= c; a ^= (c >> 12);		\
1240 		b -= c; b -= a; b ^= (a << 16);		\
1241 		c -= a; c -= b; c ^= (b >> 5);		\
1242 		a -= b; a -= c; a ^= (c >> 3);		\
1243 		b -= c; b -= a; b ^= (a << 10);		\
1244 		c -= a; c -= b; c ^= (b >> 15);		\
1245 	} while (0)
1246 
1247 static u_int32_t
1248 carp_hash(struct carp_softc *sc, u_char *src)
1249 {
1250 	u_int32_t a = 0x9e3779b9, b = sc->sc_hashkey[0], c = sc->sc_hashkey[1];
1251 
1252 	c += sc->sc_key[3] << 24;
1253 	c += sc->sc_key[2] << 16;
1254 	c += sc->sc_key[1] << 8;
1255 	c += sc->sc_key[0];
1256 	b += src[5] << 8;
1257 	b += src[4];
1258 	a += src[3] << 24;
1259 	a += src[2] << 16;
1260 	a += src[1] << 8;
1261 	a += src[0];
1262 
1263 	mix(a, b, c);
1264 	return (c);
1265 }
1266 
1267 static int
1268 carp_addrcount(struct carp_if *cif, struct in_ifaddr *ia, int type)
1269 {
1270 	struct carp_softc *vh;
1271 	struct ifaddr *ifa;
1272 	int count = 0;
1273 
1274 	TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
1275 		if ((type == CARP_COUNT_RUNNING &&
1276 		    (vh->sc_if.if_flags & (IFF_UP|IFF_RUNNING)) ==
1277 		    (IFF_UP|IFF_RUNNING)) ||
1278 		    (type == CARP_COUNT_MASTER && vh->sc_state == MASTER)) {
1279 			IFADDR_FOREACH(ifa, &vh->sc_if) {
1280 				if (ifa->ifa_addr->sa_family == AF_INET &&
1281 				    ia->ia_addr.sin_addr.s_addr ==
1282 				    ifatoia(ifa)->ia_addr.sin_addr.s_addr)
1283 					count++;
1284 			}
1285 		}
1286 	}
1287 	return (count);
1288 }
1289 
1290 int
1291 carp_iamatch(struct in_ifaddr *ia, u_char *src,
1292     u_int32_t *count, u_int32_t index)
1293 {
1294 	struct carp_softc *sc = ia->ia_ifp->if_softc;
1295 
1296 	if (carp_opts[CARPCTL_ARPBALANCE]) {
1297 		/*
1298 		 * We use the source ip to decide which virtual host should
1299 		 * handle the request. If we're master of that virtual host,
1300 		 * then we respond, otherwise, just drop the arp packet on
1301 		 * the floor.
1302 		 */
1303 
1304 		/* Count the elegible carp interfaces with this address */
1305 		if (*count == 0)
1306 			*count = carp_addrcount(
1307 			    (struct carp_if *)ia->ia_ifp->if_carpdev->if_carp,
1308 			    ia, CARP_COUNT_RUNNING);
1309 
1310 		/* This should never happen, but... */
1311 		if (*count == 0)
1312 			return (0);
1313 
1314 		if (carp_hash(sc, src) % *count == index - 1 &&
1315 		    sc->sc_state == MASTER) {
1316 			return (1);
1317 		}
1318 	} else {
1319 		if (sc->sc_state == MASTER)
1320 			return (1);
1321 	}
1322 
1323 	return (0);
1324 }
1325 
1326 #ifdef INET6
1327 struct ifaddr *
1328 carp_iamatch6(void *v, struct in6_addr *taddr)
1329 {
1330 	struct carp_if *cif = v;
1331 	struct carp_softc *vh;
1332 	struct ifaddr *ifa;
1333 
1334 	TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
1335 		IFADDR_FOREACH(ifa, &vh->sc_if) {
1336 			if (IN6_ARE_ADDR_EQUAL(taddr,
1337 			    &ifatoia6(ifa)->ia_addr.sin6_addr) &&
1338 			    ((vh->sc_if.if_flags & (IFF_UP|IFF_RUNNING)) ==
1339 			    (IFF_UP|IFF_RUNNING)) && vh->sc_state == MASTER)
1340 				return (ifa);
1341 		}
1342 	}
1343 
1344 	return (NULL);
1345 }
1346 #endif /* INET6 */
1347 
1348 struct ifnet *
1349 carp_ourether(void *v, struct ether_header *eh, u_char iftype, int src)
1350 {
1351 	struct carp_if *cif = (struct carp_if *)v;
1352 	struct carp_softc *vh;
1353 	u_int8_t *ena;
1354 
1355 	if (src)
1356 		ena = (u_int8_t *)&eh->ether_shost;
1357 	else
1358 		ena = (u_int8_t *)&eh->ether_dhost;
1359 
1360 	switch (iftype) {
1361 	case IFT_ETHER:
1362 	case IFT_FDDI:
1363 		if (ena[0] || ena[1] || ena[2] != 0x5e || ena[3] || ena[4] != 1)
1364 			return (NULL);
1365 		break;
1366 	case IFT_ISO88025:
1367 		if (ena[0] != 3 || ena[1] || ena[4] || ena[5])
1368 			return (NULL);
1369 		break;
1370 	default:
1371 		return (NULL);
1372 		break;
1373 	}
1374 
1375 	TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list)
1376 		if ((vh->sc_if.if_flags & (IFF_UP|IFF_RUNNING)) ==
1377 		    (IFF_UP|IFF_RUNNING) && vh->sc_state == MASTER &&
1378 		    !memcmp(ena, CLLADDR(vh->sc_if.if_sadl),
1379 		    ETHER_ADDR_LEN)) {
1380 			return (&vh->sc_if);
1381 		    }
1382 
1383 	return (NULL);
1384 }
1385 
1386 int
1387 carp_input(struct mbuf *m, u_int8_t *shost, u_int8_t *dhost, u_int16_t etype)
1388 {
1389 	struct ether_header eh;
1390 	struct carp_if *cif = (struct carp_if *)m->m_pkthdr.rcvif->if_carp;
1391 	struct ifnet *ifp;
1392 
1393 	memcpy(&eh.ether_shost, shost, sizeof(eh.ether_shost));
1394 	memcpy(&eh.ether_dhost, dhost, sizeof(eh.ether_dhost));
1395 	eh.ether_type = etype;
1396 
1397 	if (m->m_flags & (M_BCAST|M_MCAST)) {
1398 		struct carp_softc *vh;
1399 		struct mbuf *m0;
1400 
1401 		/*
1402 		 * XXX Should really check the list of multicast addresses
1403 		 * for each CARP interface _before_ copying.
1404 		 */
1405 		TAILQ_FOREACH(vh, &cif->vhif_vrs, sc_list) {
1406 			m0 = m_copym(m, 0, M_COPYALL, M_DONTWAIT);
1407 			if (m0 == NULL)
1408 				continue;
1409 			m0->m_pkthdr.rcvif = &vh->sc_if;
1410 			ether_input(&vh->sc_if, m0);
1411 		}
1412 		return (1);
1413 	}
1414 
1415 	ifp = carp_ourether(cif, &eh, m->m_pkthdr.rcvif->if_type, 0);
1416 	if (ifp == NULL) {
1417 		return (1);
1418 	}
1419 
1420 	m->m_pkthdr.rcvif = ifp;
1421 
1422 	bpf_mtap(ifp, m);
1423 	ifp->if_ipackets++;
1424 	ether_input(ifp, m);
1425 	return (0);
1426 }
1427 
1428 static void
1429 carp_master_down(void *v)
1430 {
1431 	struct carp_softc *sc = v;
1432 
1433 	switch (sc->sc_state) {
1434 	case INIT:
1435 		printf("%s: master_down event in INIT state\n",
1436 		    sc->sc_if.if_xname);
1437 		break;
1438 	case MASTER:
1439 		break;
1440 	case BACKUP:
1441 		CARP_LOG(sc, ("INIT -> MASTER (preempting)"));
1442 		carp_set_state(sc, MASTER);
1443 		carp_send_ad(sc);
1444 		carp_send_arp(sc);
1445 #ifdef INET6
1446 		carp_send_na(sc);
1447 #endif /* INET6 */
1448 		carp_setrun(sc, 0);
1449 		carp_setroute(sc, RTM_ADD);
1450 		break;
1451 	}
1452 }
1453 
1454 /*
1455  * When in backup state, af indicates whether to reset the master down timer
1456  * for v4 or v6. If it's set to zero, reset the ones which are already pending.
1457  */
1458 static void
1459 carp_setrun(struct carp_softc *sc, sa_family_t af)
1460 {
1461 	struct timeval tv;
1462 
1463 	if (sc->sc_carpdev == NULL) {
1464 		sc->sc_if.if_flags &= ~IFF_RUNNING;
1465 		carp_set_state(sc, INIT);
1466 		return;
1467 	}
1468 
1469 	if (sc->sc_if.if_flags & IFF_UP && sc->sc_vhid > 0 &&
1470 	    (sc->sc_naddrs || sc->sc_naddrs6) && !sc->sc_suppress) {
1471 		sc->sc_if.if_flags |= IFF_RUNNING;
1472 	} else {
1473 		sc->sc_if.if_flags &= ~IFF_RUNNING;
1474 		carp_setroute(sc, RTM_DELETE);
1475 		return;
1476 	}
1477 
1478 	switch (sc->sc_state) {
1479 	case INIT:
1480 		carp_set_state(sc, BACKUP);
1481 		carp_setroute(sc, RTM_DELETE);
1482 		carp_setrun(sc, 0);
1483 		break;
1484 	case BACKUP:
1485 		callout_stop(&sc->sc_ad_tmo);
1486 		tv.tv_sec = 3 * sc->sc_advbase;
1487 		tv.tv_usec = sc->sc_advskew * 1000000 / 256;
1488 		switch (af) {
1489 #ifdef INET
1490 		case AF_INET:
1491 			callout_schedule(&sc->sc_md_tmo, tvtohz(&tv));
1492 			break;
1493 #endif /* INET */
1494 #ifdef INET6
1495 		case AF_INET6:
1496 			callout_schedule(&sc->sc_md6_tmo, tvtohz(&tv));
1497 			break;
1498 #endif /* INET6 */
1499 		default:
1500 			if (sc->sc_naddrs)
1501 				callout_schedule(&sc->sc_md_tmo, tvtohz(&tv));
1502 			if (sc->sc_naddrs6)
1503 				callout_schedule(&sc->sc_md6_tmo, tvtohz(&tv));
1504 			break;
1505 		}
1506 		break;
1507 	case MASTER:
1508 		tv.tv_sec = sc->sc_advbase;
1509 		tv.tv_usec = sc->sc_advskew * 1000000 / 256;
1510 		callout_schedule(&sc->sc_ad_tmo, tvtohz(&tv));
1511 		break;
1512 	}
1513 }
1514 
1515 static void
1516 carp_multicast_cleanup(struct carp_softc *sc)
1517 {
1518 	struct ip_moptions *imo = &sc->sc_imo;
1519 #ifdef INET6
1520 	struct ip6_moptions *im6o = &sc->sc_im6o;
1521 #endif
1522 	u_int16_t n = imo->imo_num_memberships;
1523 
1524 	/* Clean up our own multicast memberships */
1525 	while (n-- > 0) {
1526 		if (imo->imo_membership[n] != NULL) {
1527 			in_delmulti(imo->imo_membership[n]);
1528 			imo->imo_membership[n] = NULL;
1529 		}
1530 	}
1531 	imo->imo_num_memberships = 0;
1532 	imo->imo_multicast_ifp = NULL;
1533 
1534 #ifdef INET6
1535 	while (!LIST_EMPTY(&im6o->im6o_memberships)) {
1536 		struct in6_multi_mship *imm =
1537 		    LIST_FIRST(&im6o->im6o_memberships);
1538 
1539 		LIST_REMOVE(imm, i6mm_chain);
1540 		in6_leavegroup(imm);
1541 	}
1542 	im6o->im6o_multicast_ifp = NULL;
1543 #endif
1544 
1545 	/* And any other multicast memberships */
1546 	carp_ether_purgemulti(sc);
1547 }
1548 
1549 static int
1550 carp_set_ifp(struct carp_softc *sc, struct ifnet *ifp)
1551 {
1552 	struct carp_if *cif, *ncif = NULL;
1553 	struct carp_softc *vr, *after = NULL;
1554 	int myself = 0, error = 0;
1555 	int s;
1556 
1557 	if (ifp == sc->sc_carpdev)
1558 		return (0);
1559 
1560 	if (ifp != NULL) {
1561 		if ((ifp->if_flags & IFF_MULTICAST) == 0)
1562 			return (EADDRNOTAVAIL);
1563 
1564 		if (ifp->if_type == IFT_CARP)
1565 			return (EINVAL);
1566 
1567 		if (ifp->if_carp == NULL) {
1568 			ncif = malloc(sizeof(*cif), M_IFADDR, M_NOWAIT);
1569 			if (ncif == NULL)
1570 				return (ENOBUFS);
1571 			if ((error = ifpromisc(ifp, 1))) {
1572 				free(ncif, M_IFADDR);
1573 				return (error);
1574 			}
1575 
1576 			ncif->vhif_ifp = ifp;
1577 			TAILQ_INIT(&ncif->vhif_vrs);
1578 		} else {
1579 			cif = (struct carp_if *)ifp->if_carp;
1580 			TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list)
1581 				if (vr != sc && vr->sc_vhid == sc->sc_vhid)
1582 					return (EINVAL);
1583 		}
1584 
1585 		/* detach from old interface */
1586 		if (sc->sc_carpdev != NULL)
1587 			carpdetach(sc);
1588 
1589 		/* join multicast groups */
1590 		if (sc->sc_naddrs < 0 &&
1591 		    (error = carp_join_multicast(sc)) != 0) {
1592 			if (ncif != NULL)
1593 				free(ncif, M_IFADDR);
1594 			return (error);
1595 		}
1596 
1597 #ifdef INET6
1598 		if (sc->sc_naddrs6 < 0 &&
1599 		    (error = carp_join_multicast6(sc)) != 0) {
1600 			if (ncif != NULL)
1601 				free(ncif, M_IFADDR);
1602 			carp_multicast_cleanup(sc);
1603 			return (error);
1604 		}
1605 #endif
1606 
1607 		/* attach carp interface to physical interface */
1608 		if (ncif != NULL)
1609 			ifp->if_carp = (void *)ncif;
1610 		sc->sc_carpdev = ifp;
1611 		sc->sc_if.if_capabilities = ifp->if_capabilities &
1612 		             (IFCAP_TSOv4 | IFCAP_TSOv6 |
1613                              IFCAP_CSUM_IPv4_Tx|IFCAP_CSUM_IPv4_Rx|
1614                              IFCAP_CSUM_TCPv4_Tx|IFCAP_CSUM_TCPv4_Rx|
1615                              IFCAP_CSUM_UDPv4_Tx|IFCAP_CSUM_UDPv4_Rx|
1616                              IFCAP_CSUM_TCPv6_Tx|IFCAP_CSUM_TCPv6_Rx|
1617                              IFCAP_CSUM_UDPv6_Tx|IFCAP_CSUM_UDPv6_Rx);
1618 
1619 		cif = (struct carp_if *)ifp->if_carp;
1620 		TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list) {
1621 			if (vr == sc)
1622 				myself = 1;
1623 			if (vr->sc_vhid < sc->sc_vhid)
1624 				after = vr;
1625 		}
1626 
1627 		if (!myself) {
1628 			/* We're trying to keep things in order */
1629 			if (after == NULL) {
1630 				TAILQ_INSERT_TAIL(&cif->vhif_vrs, sc, sc_list);
1631 			} else {
1632 				TAILQ_INSERT_AFTER(&cif->vhif_vrs, after,
1633 				    sc, sc_list);
1634 			}
1635 			cif->vhif_nvrs++;
1636 		}
1637 		if (sc->sc_naddrs || sc->sc_naddrs6)
1638 			sc->sc_if.if_flags |= IFF_UP;
1639 		carp_set_enaddr(sc);
1640 		KERNEL_LOCK(1, NULL);
1641 		s = splnet();
1642 		/* XXX linkstatehooks establish */
1643 		carp_carpdev_state(ifp);
1644 		splx(s);
1645 		KERNEL_UNLOCK_ONE(NULL);
1646 	} else {
1647 		carpdetach(sc);
1648 		sc->sc_if.if_flags &= ~(IFF_UP|IFF_RUNNING);
1649 	}
1650 	return (0);
1651 }
1652 
1653 static void
1654 carp_set_enaddr(struct carp_softc *sc)
1655 {
1656 	uint8_t enaddr[ETHER_ADDR_LEN];
1657 	if (sc->sc_carpdev && sc->sc_carpdev->if_type == IFT_ISO88025) {
1658 		enaddr[0] = 3;
1659 		enaddr[1] = 0;
1660 		enaddr[2] = 0x40 >> (sc->sc_vhid - 1);
1661 		enaddr[3] = 0x40000 >> (sc->sc_vhid - 1);
1662 		enaddr[4] = 0;
1663 		enaddr[5] = 0;
1664 	} else {
1665 		enaddr[0] = 0;
1666 		enaddr[1] = 0;
1667 		enaddr[2] = 0x5e;
1668 		enaddr[3] = 0;
1669 		enaddr[4] = 1;
1670 		enaddr[5] = sc->sc_vhid;
1671 	}
1672 	if_set_sadl(&sc->sc_if, enaddr, sizeof(enaddr), false);
1673 }
1674 
1675 #if 0
1676 static void
1677 carp_addr_updated(void *v)
1678 {
1679 	struct carp_softc *sc = (struct carp_softc *) v;
1680 	struct ifaddr *ifa;
1681 	int new_naddrs = 0, new_naddrs6 = 0;
1682 
1683 	IFADDR_FOREACH(ifa, &sc->sc_if) {
1684 		if (ifa->ifa_addr->sa_family == AF_INET)
1685 			new_naddrs++;
1686 		else if (ifa->ifa_addr->sa_family == AF_INET6)
1687 			new_naddrs6++;
1688 	}
1689 
1690 	/* Handle a callback after SIOCDIFADDR */
1691 	if (new_naddrs < sc->sc_naddrs || new_naddrs6 < sc->sc_naddrs6) {
1692 		struct in_addr mc_addr;
1693 
1694 		sc->sc_naddrs = new_naddrs;
1695 		sc->sc_naddrs6 = new_naddrs6;
1696 
1697 		/* Re-establish multicast membership removed by in_control */
1698 		mc_addr.s_addr = INADDR_CARP_GROUP;
1699 		if (!in_multi_group(mc_addr, &sc->sc_if, 0)) {
1700 			memset(&sc->sc_imo, 0, sizeof(sc->sc_imo));
1701 
1702 			if (sc->sc_carpdev != NULL && sc->sc_naddrs > 0)
1703 				carp_join_multicast(sc);
1704 		}
1705 
1706 		if (sc->sc_naddrs == 0 && sc->sc_naddrs6 == 0) {
1707 			sc->sc_if.if_flags &= ~IFF_UP;
1708 			carp_set_state(sc, INIT);
1709 		} else
1710 			carp_hmac_prepare(sc);
1711 	}
1712 
1713 	carp_setrun(sc, 0);
1714 }
1715 #endif
1716 
1717 static int
1718 carp_set_addr(struct carp_softc *sc, struct sockaddr_in *sin)
1719 {
1720 	struct ifnet *ifp = sc->sc_carpdev;
1721 	struct in_ifaddr *ia, *ia_if;
1722 	int error = 0;
1723 
1724 	if (sin->sin_addr.s_addr == 0) {
1725 		if (!(sc->sc_if.if_flags & IFF_UP))
1726 			carp_set_state(sc, INIT);
1727 		if (sc->sc_naddrs)
1728 			sc->sc_if.if_flags |= IFF_UP;
1729 		carp_setrun(sc, 0);
1730 		return (0);
1731 	}
1732 
1733 	/* we have to do this by hand to ensure we don't match on ourselves */
1734 	ia_if = NULL;
1735 	for (ia = TAILQ_FIRST(&in_ifaddrhead); ia;
1736 	    ia = TAILQ_NEXT(ia, ia_list)) {
1737 
1738 		/* and, yeah, we need a multicast-capable iface too */
1739 		if (ia->ia_ifp != &sc->sc_if &&
1740 		    ia->ia_ifp->if_type != IFT_CARP &&
1741 		    (ia->ia_ifp->if_flags & IFF_MULTICAST) &&
1742 		    (sin->sin_addr.s_addr & ia->ia_subnetmask) ==
1743 		    ia->ia_subnet) {
1744 			if (!ia_if)
1745 				ia_if = ia;
1746 		}
1747 	}
1748 
1749 	if (ia_if) {
1750 		ia = ia_if;
1751 		if (ifp) {
1752 			if (ifp != ia->ia_ifp)
1753 				return (EADDRNOTAVAIL);
1754 		} else {
1755 			ifp = ia->ia_ifp;
1756 		}
1757 	}
1758 
1759 	if ((error = carp_set_ifp(sc, ifp)))
1760 		return (error);
1761 
1762 	if (sc->sc_carpdev == NULL)
1763 		return (EADDRNOTAVAIL);
1764 
1765 	if (sc->sc_naddrs == 0 && (error = carp_join_multicast(sc)) != 0)
1766 		return (error);
1767 
1768 	sc->sc_naddrs++;
1769 	if (sc->sc_carpdev != NULL)
1770 		sc->sc_if.if_flags |= IFF_UP;
1771 
1772 	carp_set_state(sc, INIT);
1773 	carp_setrun(sc, 0);
1774 
1775 	/*
1776 	 * Hook if_addrhooks so that we get a callback after in_ifinit has run,
1777 	 * to correct any inappropriate routes that it inserted.
1778 	 */
1779 	if (sc->ah_cookie == 0) {
1780 		/* XXX link address hook */
1781 	}
1782 
1783 	return (0);
1784 }
1785 
1786 static int
1787 carp_join_multicast(struct carp_softc *sc)
1788 {
1789 	struct ip_moptions *imo = &sc->sc_imo, tmpimo;
1790 	struct in_addr addr;
1791 
1792 	memset(&tmpimo, 0, sizeof(tmpimo));
1793 	addr.s_addr = INADDR_CARP_GROUP;
1794 	if ((tmpimo.imo_membership[0] =
1795 	    in_addmulti(&addr, &sc->sc_if)) == NULL) {
1796 		return (ENOBUFS);
1797 	}
1798 
1799 	imo->imo_membership[0] = tmpimo.imo_membership[0];
1800 	imo->imo_num_memberships = 1;
1801 	imo->imo_multicast_ifp = &sc->sc_if;
1802 	imo->imo_multicast_ttl = CARP_DFLTTL;
1803 	imo->imo_multicast_loop = 0;
1804 	return (0);
1805 }
1806 
1807 
1808 #ifdef INET6
1809 static int
1810 carp_set_addr6(struct carp_softc *sc, struct sockaddr_in6 *sin6)
1811 {
1812 	struct ifnet *ifp = sc->sc_carpdev;
1813 	struct in6_ifaddr *ia, *ia_if;
1814 	int error = 0;
1815 
1816 	if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) {
1817 		if (!(sc->sc_if.if_flags & IFF_UP))
1818 			carp_set_state(sc, INIT);
1819 		if (sc->sc_naddrs6)
1820 			sc->sc_if.if_flags |= IFF_UP;
1821 		carp_setrun(sc, 0);
1822 		return (0);
1823 	}
1824 
1825 	/* we have to do this by hand to ensure we don't match on ourselves */
1826 	ia_if = NULL;
1827 	for (ia = in6_ifaddr; ia; ia = ia->ia_next) {
1828 		int i;
1829 
1830 		for (i = 0; i < 4; i++) {
1831 			if ((sin6->sin6_addr.s6_addr32[i] &
1832 			    ia->ia_prefixmask.sin6_addr.s6_addr32[i]) !=
1833 			    (ia->ia_addr.sin6_addr.s6_addr32[i] &
1834 			    ia->ia_prefixmask.sin6_addr.s6_addr32[i]))
1835 				break;
1836 		}
1837 		/* and, yeah, we need a multicast-capable iface too */
1838 		if (ia->ia_ifp != &sc->sc_if &&
1839 		    ia->ia_ifp->if_type != IFT_CARP &&
1840 		    (ia->ia_ifp->if_flags & IFF_MULTICAST) &&
1841 		    (i == 4)) {
1842 			if (!ia_if)
1843 				ia_if = ia;
1844 		}
1845 	}
1846 
1847 	if (ia_if) {
1848 		ia = ia_if;
1849 		if (sc->sc_carpdev) {
1850 			if (sc->sc_carpdev != ia->ia_ifp)
1851 				return (EADDRNOTAVAIL);
1852 		} else {
1853 			ifp = ia->ia_ifp;
1854 		}
1855 	}
1856 
1857 	if ((error = carp_set_ifp(sc, ifp)))
1858 		return (error);
1859 
1860 	if (sc->sc_carpdev == NULL)
1861 		return (EADDRNOTAVAIL);
1862 
1863 	if (sc->sc_naddrs6 == 0 && (error = carp_join_multicast6(sc)) != 0)
1864 		return (error);
1865 
1866 	sc->sc_naddrs6++;
1867 	if (sc->sc_carpdev != NULL)
1868 		sc->sc_if.if_flags |= IFF_UP;
1869 	carp_set_state(sc, INIT);
1870 	carp_setrun(sc, 0);
1871 
1872 	return (0);
1873 }
1874 
1875 static int
1876 carp_join_multicast6(struct carp_softc *sc)
1877 {
1878 	struct in6_multi_mship *imm, *imm2;
1879 	struct ip6_moptions *im6o = &sc->sc_im6o;
1880 	struct sockaddr_in6 addr6;
1881 	int error;
1882 
1883 	/* Join IPv6 CARP multicast group */
1884 	memset(&addr6, 0, sizeof(addr6));
1885 	addr6.sin6_family = AF_INET6;
1886 	addr6.sin6_len = sizeof(addr6);
1887 	addr6.sin6_addr.s6_addr16[0] = htons(0xff02);
1888 	addr6.sin6_addr.s6_addr16[1] = htons(sc->sc_if.if_index);
1889 	addr6.sin6_addr.s6_addr8[15] = 0x12;
1890 	if ((imm = in6_joingroup(&sc->sc_if,
1891 	    &addr6.sin6_addr, &error, 0)) == NULL) {
1892 		return (error);
1893 	}
1894 	/* join solicited multicast address */
1895 	memset(&addr6.sin6_addr, 0, sizeof(addr6.sin6_addr));
1896 	addr6.sin6_addr.s6_addr16[0] = htons(0xff02);
1897 	addr6.sin6_addr.s6_addr16[1] = htons(sc->sc_if.if_index);
1898 	addr6.sin6_addr.s6_addr32[1] = 0;
1899 	addr6.sin6_addr.s6_addr32[2] = htonl(1);
1900 	addr6.sin6_addr.s6_addr32[3] = 0;
1901 	addr6.sin6_addr.s6_addr8[12] = 0xff;
1902 	if ((imm2 = in6_joingroup(&sc->sc_if,
1903 	    &addr6.sin6_addr, &error, 0)) == NULL) {
1904 		in6_leavegroup(imm);
1905 		return (error);
1906 	}
1907 
1908 	/* apply v6 multicast membership */
1909 	im6o->im6o_multicast_ifp = &sc->sc_if;
1910 	if (imm)
1911 		LIST_INSERT_HEAD(&im6o->im6o_memberships, imm,
1912 		    i6mm_chain);
1913 	if (imm2)
1914 		LIST_INSERT_HEAD(&im6o->im6o_memberships, imm2,
1915 		    i6mm_chain);
1916 
1917 	return (0);
1918 }
1919 
1920 #endif /* INET6 */
1921 
1922 static int
1923 carp_ioctl(struct ifnet *ifp, u_long cmd, void *data)
1924 {
1925 	struct lwp *l = curlwp;		/* XXX */
1926 	struct carp_softc *sc = ifp->if_softc, *vr;
1927 	struct carpreq carpr;
1928 	struct ifaddr *ifa;
1929 	struct ifreq *ifr;
1930 	struct ifnet *cdev = NULL;
1931 	int error = 0;
1932 
1933 	ifa = (struct ifaddr *)data;
1934 	ifr = (struct ifreq *)data;
1935 
1936 	switch (cmd) {
1937 	case SIOCINITIFADDR:
1938 		switch (ifa->ifa_addr->sa_family) {
1939 #ifdef INET
1940 		case AF_INET:
1941 			sc->sc_if.if_flags |= IFF_UP;
1942 			memcpy(ifa->ifa_dstaddr, ifa->ifa_addr,
1943 			    sizeof(struct sockaddr));
1944 			error = carp_set_addr(sc, satosin(ifa->ifa_addr));
1945 			break;
1946 #endif /* INET */
1947 #ifdef INET6
1948 		case AF_INET6:
1949 			sc->sc_if.if_flags|= IFF_UP;
1950 			error = carp_set_addr6(sc, satosin6(ifa->ifa_addr));
1951 			break;
1952 #endif /* INET6 */
1953 		default:
1954 			error = EAFNOSUPPORT;
1955 			break;
1956 		}
1957 		break;
1958 
1959 	case SIOCSIFFLAGS:
1960 		if ((error = ifioctl_common(ifp, cmd, data)) != 0)
1961 			break;
1962 		if (sc->sc_state != INIT && !(ifr->ifr_flags & IFF_UP)) {
1963 			callout_stop(&sc->sc_ad_tmo);
1964 			callout_stop(&sc->sc_md_tmo);
1965 			callout_stop(&sc->sc_md6_tmo);
1966 			if (sc->sc_state == MASTER) {
1967 				/* we need the interface up to bow out */
1968 				sc->sc_if.if_flags |= IFF_UP;
1969 				sc->sc_bow_out = 1;
1970 				carp_send_ad(sc);
1971 			}
1972 			sc->sc_if.if_flags &= ~IFF_UP;
1973 			carp_set_state(sc, INIT);
1974 			carp_setrun(sc, 0);
1975 		} else if (sc->sc_state == INIT && (ifr->ifr_flags & IFF_UP)) {
1976 			sc->sc_if.if_flags |= IFF_UP;
1977 			carp_setrun(sc, 0);
1978 		}
1979 		break;
1980 
1981 	case SIOCSVH:
1982 		if (l == NULL)
1983 			break;
1984 		if ((error = kauth_authorize_network(l->l_cred,
1985 		    KAUTH_NETWORK_INTERFACE,
1986 		    KAUTH_REQ_NETWORK_INTERFACE_SETPRIV, ifp, (void *)cmd,
1987 		    NULL)) != 0)
1988 			break;
1989 		if ((error = copyin(ifr->ifr_data, &carpr, sizeof carpr)))
1990 			break;
1991 		error = 1;
1992 		if (carpr.carpr_carpdev[0] != '\0' &&
1993 		    (cdev = ifunit(carpr.carpr_carpdev)) == NULL)
1994 			return (EINVAL);
1995 		if ((error = carp_set_ifp(sc, cdev)))
1996 			return (error);
1997 		if (sc->sc_state != INIT && carpr.carpr_state != sc->sc_state) {
1998 			switch (carpr.carpr_state) {
1999 			case BACKUP:
2000 				callout_stop(&sc->sc_ad_tmo);
2001 				carp_set_state(sc, BACKUP);
2002 				carp_setrun(sc, 0);
2003 				carp_setroute(sc, RTM_DELETE);
2004 				break;
2005 			case MASTER:
2006 				carp_master_down(sc);
2007 				break;
2008 			default:
2009 				break;
2010 			}
2011 		}
2012 		if (carpr.carpr_vhid > 0) {
2013 			if (carpr.carpr_vhid > 255) {
2014 				error = EINVAL;
2015 				break;
2016 			}
2017 			if (sc->sc_carpdev) {
2018 				struct carp_if *cif;
2019 				cif = (struct carp_if *)sc->sc_carpdev->if_carp;
2020 				TAILQ_FOREACH(vr, &cif->vhif_vrs, sc_list)
2021 					if (vr != sc &&
2022 					    vr->sc_vhid == carpr.carpr_vhid)
2023 						return (EINVAL);
2024 			}
2025 			sc->sc_vhid = carpr.carpr_vhid;
2026 			carp_set_enaddr(sc);
2027 			carp_set_state(sc, INIT);
2028 			error--;
2029 		}
2030 		if (carpr.carpr_advbase > 0 || carpr.carpr_advskew > 0) {
2031 			if (carpr.carpr_advskew > 254) {
2032 				error = EINVAL;
2033 				break;
2034 			}
2035 			if (carpr.carpr_advbase > 255) {
2036 				error = EINVAL;
2037 				break;
2038 			}
2039 			sc->sc_advbase = carpr.carpr_advbase;
2040 			sc->sc_advskew = carpr.carpr_advskew;
2041 			error--;
2042 		}
2043 		memcpy(sc->sc_key, carpr.carpr_key, sizeof(sc->sc_key));
2044 		if (error > 0)
2045 			error = EINVAL;
2046 		else {
2047 			error = 0;
2048 			carp_setrun(sc, 0);
2049 		}
2050 		break;
2051 
2052 	case SIOCGVH:
2053 		memset(&carpr, 0, sizeof(carpr));
2054 		if (sc->sc_carpdev != NULL)
2055 			strlcpy(carpr.carpr_carpdev, sc->sc_carpdev->if_xname,
2056 			    IFNAMSIZ);
2057 		carpr.carpr_state = sc->sc_state;
2058 		carpr.carpr_vhid = sc->sc_vhid;
2059 		carpr.carpr_advbase = sc->sc_advbase;
2060 		carpr.carpr_advskew = sc->sc_advskew;
2061 
2062 		if ((l != NULL) && (error = kauth_authorize_network(l->l_cred,
2063 		    KAUTH_NETWORK_INTERFACE,
2064 		    KAUTH_REQ_NETWORK_INTERFACE_SETPRIV, ifp, (void *)cmd,
2065 		    NULL)) == 0)
2066 			memcpy(carpr.carpr_key, sc->sc_key,
2067 			    sizeof(carpr.carpr_key));
2068 		error = copyout(&carpr, ifr->ifr_data, sizeof(carpr));
2069 		break;
2070 
2071 	case SIOCADDMULTI:
2072 		error = carp_ether_addmulti(sc, ifr);
2073 		break;
2074 
2075 	case SIOCDELMULTI:
2076 		error = carp_ether_delmulti(sc, ifr);
2077 		break;
2078 
2079 	case SIOCSIFCAP:
2080 		if ((error = ifioctl_common(ifp, cmd, data)) == ENETRESET)
2081 			error = 0;
2082 		break;
2083 
2084 	default:
2085 		error = ether_ioctl(ifp, cmd, data);
2086 	}
2087 
2088 	carp_hmac_prepare(sc);
2089 	return (error);
2090 }
2091 
2092 
2093 /*
2094  * Start output on carp interface. This function should never be called.
2095  */
2096 static void
2097 carp_start(struct ifnet *ifp)
2098 {
2099 #ifdef DEBUG
2100 	printf("%s: start called\n", ifp->if_xname);
2101 #endif
2102 }
2103 
2104 int
2105 carp_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *sa,
2106     const struct rtentry *rt)
2107 {
2108 	struct carp_softc *sc = ((struct carp_softc *)ifp->if_softc);
2109 	KASSERT(KERNEL_LOCKED_P());
2110 
2111 	if (sc->sc_carpdev != NULL && sc->sc_state == MASTER) {
2112 		return (sc->sc_carpdev->if_output(ifp, m, sa, rt));
2113 	} else {
2114 		m_freem(m);
2115 		return (ENETUNREACH);
2116 	}
2117 }
2118 
2119 static void
2120 carp_set_state(struct carp_softc *sc, int state)
2121 {
2122 	static const char *carp_states[] = { CARP_STATES };
2123 	if (sc->sc_state == state)
2124 		return;
2125 
2126 	CARP_LOG(sc, ("state transition from: %s -> to: %s", carp_states[sc->sc_state], carp_states[state]));
2127 
2128 	sc->sc_state = state;
2129 	switch (state) {
2130 	case BACKUP:
2131 		sc->sc_if.if_link_state = LINK_STATE_DOWN;
2132 		break;
2133 	case MASTER:
2134 		sc->sc_if.if_link_state = LINK_STATE_UP;
2135 		break;
2136 	default:
2137 		sc->sc_if.if_link_state = LINK_STATE_UNKNOWN;
2138 		break;
2139 	}
2140 	rt_ifmsg(&sc->sc_if);
2141 }
2142 
2143 void
2144 carp_carpdev_state(void *v)
2145 {
2146 	struct carp_if *cif;
2147 	struct carp_softc *sc;
2148 	struct ifnet *ifp = v;
2149 
2150 	if (ifp->if_type == IFT_CARP)
2151 		return;
2152 
2153 	cif = (struct carp_if *)ifp->if_carp;
2154 
2155 	TAILQ_FOREACH(sc, &cif->vhif_vrs, sc_list) {
2156 		int suppressed = sc->sc_suppress;
2157 
2158 		if (sc->sc_carpdev->if_link_state == LINK_STATE_DOWN ||
2159 		    !(sc->sc_carpdev->if_flags & IFF_UP)) {
2160 			sc->sc_if.if_flags &= ~IFF_RUNNING;
2161 			callout_stop(&sc->sc_ad_tmo);
2162 			callout_stop(&sc->sc_md_tmo);
2163 			callout_stop(&sc->sc_md6_tmo);
2164 			carp_set_state(sc, INIT);
2165 			sc->sc_suppress = 1;
2166 			carp_setrun(sc, 0);
2167 			if (!suppressed) {
2168 				carp_suppress_preempt++;
2169 				if (carp_suppress_preempt == 1)
2170 					carp_send_ad_all();
2171 			}
2172 		} else {
2173 			carp_set_state(sc, INIT);
2174 			sc->sc_suppress = 0;
2175 			carp_setrun(sc, 0);
2176 			if (suppressed)
2177 				carp_suppress_preempt--;
2178 		}
2179 	}
2180 }
2181 
2182 static int
2183 carp_ether_addmulti(struct carp_softc *sc, struct ifreq *ifr)
2184 {
2185 	const struct sockaddr *sa = ifreq_getaddr(SIOCADDMULTI, ifr);
2186 	struct ifnet *ifp;
2187 	struct carp_mc_entry *mc;
2188 	u_int8_t addrlo[ETHER_ADDR_LEN], addrhi[ETHER_ADDR_LEN];
2189 	int error;
2190 
2191 	ifp = sc->sc_carpdev;
2192 	if (ifp == NULL)
2193 		return (EINVAL);
2194 
2195 	error = ether_addmulti(sa, &sc->sc_ac);
2196 	if (error != ENETRESET)
2197 		return (error);
2198 
2199 	/*
2200 	 * This is new multicast address.  We have to tell parent
2201 	 * about it.  Also, remember this multicast address so that
2202 	 * we can delete them on unconfigure.
2203 	 */
2204 	mc = malloc(sizeof(struct carp_mc_entry), M_DEVBUF, M_NOWAIT);
2205 	if (mc == NULL) {
2206 		error = ENOMEM;
2207 		goto alloc_failed;
2208 	}
2209 
2210 	/*
2211 	 * As ether_addmulti() returns ENETRESET, following two
2212 	 * statement shouldn't fail.
2213 	 */
2214 	(void)ether_multiaddr(sa, addrlo, addrhi);
2215 	ETHER_LOOKUP_MULTI(addrlo, addrhi, &sc->sc_ac, mc->mc_enm);
2216 	memcpy(&mc->mc_addr, sa, sa->sa_len);
2217 	LIST_INSERT_HEAD(&sc->carp_mc_listhead, mc, mc_entries);
2218 
2219 	error = if_mcast_op(ifp, SIOCADDMULTI, sa);
2220 	if (error != 0)
2221 		goto ioctl_failed;
2222 
2223 	return (error);
2224 
2225  ioctl_failed:
2226 	LIST_REMOVE(mc, mc_entries);
2227 	free(mc, M_DEVBUF);
2228  alloc_failed:
2229 	(void)ether_delmulti(sa, &sc->sc_ac);
2230 
2231 	return (error);
2232 }
2233 
2234 static int
2235 carp_ether_delmulti(struct carp_softc *sc, struct ifreq *ifr)
2236 {
2237 	const struct sockaddr *sa = ifreq_getaddr(SIOCDELMULTI, ifr);
2238 	struct ifnet *ifp;
2239 	struct ether_multi *enm;
2240 	struct carp_mc_entry *mc;
2241 	u_int8_t addrlo[ETHER_ADDR_LEN], addrhi[ETHER_ADDR_LEN];
2242 	int error;
2243 
2244 	ifp = sc->sc_carpdev;
2245 	if (ifp == NULL)
2246 		return (EINVAL);
2247 
2248 	/*
2249 	 * Find a key to lookup carp_mc_entry.  We have to do this
2250 	 * before calling ether_delmulti for obvious reason.
2251 	 */
2252 	if ((error = ether_multiaddr(sa, addrlo, addrhi)) != 0)
2253 		return (error);
2254 	ETHER_LOOKUP_MULTI(addrlo, addrhi, &sc->sc_ac, enm);
2255 	if (enm == NULL)
2256 		return (EINVAL);
2257 
2258 	LIST_FOREACH(mc, &sc->carp_mc_listhead, mc_entries)
2259 		if (mc->mc_enm == enm)
2260 			break;
2261 
2262 	/* We won't delete entries we didn't add */
2263 	if (mc == NULL)
2264 		return (EINVAL);
2265 
2266 	error = ether_delmulti(sa, &sc->sc_ac);
2267 	if (error != ENETRESET)
2268 		return (error);
2269 
2270 	/* We no longer use this multicast address.  Tell parent so. */
2271 	error = if_mcast_op(ifp, SIOCDELMULTI, sa);
2272 	if (error == 0) {
2273 		/* And forget about this address. */
2274 		LIST_REMOVE(mc, mc_entries);
2275 		free(mc, M_DEVBUF);
2276 	} else
2277 		(void)ether_addmulti(sa, &sc->sc_ac);
2278 	return (error);
2279 }
2280 
2281 /*
2282  * Delete any multicast address we have asked to add from parent
2283  * interface.  Called when the carp is being unconfigured.
2284  */
2285 static void
2286 carp_ether_purgemulti(struct carp_softc *sc)
2287 {
2288 	struct ifnet *ifp = sc->sc_carpdev;		/* Parent. */
2289 	struct carp_mc_entry *mc;
2290 
2291 	if (ifp == NULL)
2292 		return;
2293 
2294 	while ((mc = LIST_FIRST(&sc->carp_mc_listhead)) != NULL) {
2295 		(void)if_mcast_op(ifp, SIOCDELMULTI, sstosa(&mc->mc_addr));
2296 		LIST_REMOVE(mc, mc_entries);
2297 		free(mc, M_DEVBUF);
2298 	}
2299 }
2300 
2301 static int
2302 sysctl_net_inet_carp_stats(SYSCTLFN_ARGS)
2303 {
2304 
2305 	return (NETSTAT_SYSCTL(carpstat_percpu, CARP_NSTATS));
2306 }
2307 
2308 void
2309 carp_init(void)
2310 {
2311 
2312 	sysctl_net_inet_carp_setup(NULL);
2313 #ifdef MBUFTRACE
2314 	MOWNER_ATTACH(&carp_proto_mowner_rx);
2315 	MOWNER_ATTACH(&carp_proto_mowner_tx);
2316 	MOWNER_ATTACH(&carp_proto6_mowner_rx);
2317 	MOWNER_ATTACH(&carp_proto6_mowner_tx);
2318 #endif
2319 }
2320 
2321 static void
2322 sysctl_net_inet_carp_setup(struct sysctllog **clog)
2323 {
2324 
2325 	sysctl_createv(clog, 0, NULL, NULL,
2326 		       CTLFLAG_PERMANENT,
2327 		       CTLTYPE_NODE, "inet", NULL,
2328 		       NULL, 0, NULL, 0,
2329 		       CTL_NET, PF_INET, CTL_EOL);
2330 	sysctl_createv(clog, 0, NULL, NULL,
2331 		       CTLFLAG_PERMANENT,
2332 		       CTLTYPE_NODE, "carp",
2333 		       SYSCTL_DESCR("CARP related settings"),
2334 		       NULL, 0, NULL, 0,
2335 		       CTL_NET, PF_INET, IPPROTO_CARP, CTL_EOL);
2336 
2337 	sysctl_createv(clog, 0, NULL, NULL,
2338 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2339 		       CTLTYPE_INT, "preempt",
2340 		       SYSCTL_DESCR("Enable CARP Preempt"),
2341 		       NULL, 0, &carp_opts[CARPCTL_PREEMPT], 0,
2342 		       CTL_NET, PF_INET, IPPROTO_CARP,
2343 		       CTL_CREATE, CTL_EOL);
2344 	sysctl_createv(clog, 0, NULL, NULL,
2345 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2346 		       CTLTYPE_INT, "arpbalance",
2347 		       SYSCTL_DESCR("Enable ARP balancing"),
2348 		       NULL, 0, &carp_opts[CARPCTL_ARPBALANCE], 0,
2349 		       CTL_NET, PF_INET, IPPROTO_CARP,
2350 		       CTL_CREATE, CTL_EOL);
2351 	sysctl_createv(clog, 0, NULL, NULL,
2352 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2353 		       CTLTYPE_INT, "allow",
2354 		       SYSCTL_DESCR("Enable CARP"),
2355 		       NULL, 0, &carp_opts[CARPCTL_ALLOW], 0,
2356 		       CTL_NET, PF_INET, IPPROTO_CARP,
2357 		       CTL_CREATE, CTL_EOL);
2358 	sysctl_createv(clog, 0, NULL, NULL,
2359 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2360 		       CTLTYPE_INT, "log",
2361 		       SYSCTL_DESCR("CARP logging"),
2362 		       NULL, 0, &carp_opts[CARPCTL_LOG], 0,
2363 		       CTL_NET, PF_INET, IPPROTO_CARP,
2364 		       CTL_CREATE, CTL_EOL);
2365 	sysctl_createv(clog, 0, NULL, NULL,
2366 		       CTLFLAG_PERMANENT,
2367 		       CTLTYPE_STRUCT, "stats",
2368 		       SYSCTL_DESCR("CARP statistics"),
2369 		       sysctl_net_inet_carp_stats, 0, NULL, 0,
2370 		       CTL_NET, PF_INET, IPPROTO_CARP, CARPCTL_STATS,
2371 		       CTL_EOL);
2372 }
2373